Refuse disposal system

ABSTRACT

A refuse disposal method for disposing of garbage, trash, and similar refuse in which the refuse is ground to reduce its volume, irradiated and compacted, and may include steps for utilizing part or all of the components of the refuse.

United States Patent 1111 3,604,179

[72] Inventor Norman 8. Lund 2,807,549 9/1957 Brasch 53/21 P. O. Box 246, elbourne, Fla. 32901 3,086,717 4/1963 Vroom 241/24 [21] Appl. Nov 778,686 3,323,575 6/1967 Greenfield... 99/149 [22] Filed Nov. 25, 1968 3,330,088 7/1967 Dunlea 53/24 [45] Patented Sept. 14, 1971 3,339,475 9/1967 Martin 99/228 3,451,185 6/1969 Tezuka..... 53/24X 3,451,190 6/1969 Tezuka..... 53/124 1 1 REFUSE DISPOSAL SYSTEM 3,462,275 8/1969 Bellamy.... 99/149 x 5 C im 2 Dr g g 3,477,649 1 1/1969 Dalberg 241/24 [52] US. Cl 53/23, 26352 2/1968 Greenfield 159/13 53/21 FC,53/24,53/1l1 RC, 99/149, 99/228,

241 3 24 24 3,236,743 2/1966 Plerson l95/l38 [51] Int. Cl 1365b 55/16, 3524594 8/1970 Anderson- 241/19 3 02 S 25/00 3,528,769 9/l970 Lyons 24l/24X 0' Search l 23, Prinmry Exarniner-Wayne A, Morse, J1.

25; 241/243; 99/228, 149 Attorneys-William M. Hobby and Robert W. Duckworth [56] References Cited UNITED STATES PATENTS ABSTRACT: A refuse disposal method for disposing of garl,101,129 6/1914 Kitchen 99/ 149 bage, trash, and similar refuse in which the refuse is ground to 1,215,254 2/1917 Darden 99/228 reduce its volume, irradiated and compacted, and may include 2,200,677 5/1940 Petersen 241/24 steps for utilizing part or all of the components of the refuse.

.9; 5/ 9 50 ('afier ll 57pm 5pdm/r (hm warty Z/Mfifl/Of A/l/ C 2 Packager 36 Meia/s Wafer PATENTED SEP] 4 IHYI mug REFUSE DISPOSAL SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention g The present invention relates to refuse disposal and more particularly to a system for the safe and economical disposal of garbage, trash and related wastes and which is adapted for use with systems of reuse of components of refuse and to avoid the pollution problems of present systems of refuse disposal.

By refuse I mean dry waste such as garbage, rubbish and ashes as distinguished from liquid waste such as sewage. Garbage is referred to as waste from preparation and consumption of food while rubbish means nonputrescible solid wastes such as paper, wood, metal, glass, and plastic, but excluding ashes.

Refuse is normally stored in trash cans, or the like, on the user premises such as a house or industrial plant, then collected for transportation to the disposal site and finally disposed. This invention concerns only the steps of disposing: of the refuse once delivered to the disposal site.

Disposal of refuse produces many serious health hazards, especially in areas of large population concentration suchas may be found in our large metropolitan areas. Refuse may provide a source of food for disease-carrying rodents and in-"J sects, when not burned, and produces significant atmospheric pollution if it is burned. If the refuse is buried it produces surface and ground water pollution and unless sufficiently compacted, leaves an unsatisfactory landfill, which tends to settle unevenly and may result in dangerous voids under the surface of the earth.

2. Description of the Prior Art In the past it has been common practice to dispose of refuse by burning it in incinerators which may be specially'designed for refuse disposal. The ash from the incinerator may be bu-' ried but present day incinerators produce large amounts of atmospheric pollution and destroys most of the useful elements of the refuse without reducing the volume of portions thereof such as metal cans, and the like.

Dumping refuse in water or on land has been commonly" used in the past but is coming into disuse because of unsightliness, pollution, odors and the breeding of insects and rodents in land dumps and because much of the refuse floats back to beaches when dumped in large bodies ofwater.

It has also been suggested to discharge garbage into sewage systems after grinding it and this is commonly done with home grinder or garbage disposals connected to kitchen sinks. However, this is not practical with the larger volume of refuse which is the trash such as paper, metal, glass, and the like.

Another method that has been used with only limited success but with greater future potential is the reclamation of refuse. This may be done by separating such items as large volumes of paper, metal and glass for reuse and by separating garbage for feeding to pigs. Garbage to be fed to pigs is required to be disinfected to prevent the spread of disease and states normally require that such garbage be cooked prior to being used as animal food. Falling within this category of reclamation is the compositing of garbage by biochemical alteration to provide a usable humus, or the like and garbage; may also be cooked down for its salvable grease.

Finally several methods of disposing of refuse have been proposed which grind the waste to reduce the volume and either bury the ground waste or remove moisture and burn it. These methods have produced satisfactory results but still produce atmospheric pollution when burned and water pollution when buried or dumped in large bodies of water. Means have been suggested for reducing the atmospheric pollution when burning this refuse but this has not generally been sufficiently economical or effective.

SUMMARY OF THE INVENTION A refuse disposal method has been provided having a combination of steps including grinding the refuse, separating out certain components of the ground refuse, such as metals, and

The sterilized slurry could alternatively mixing with water to form a slurry. A second grinding of the slurry provides a more thoroughly mixed ground slurry for irradiating in a radiation sterilizer and removing liquid from the slurry for feeding back to an earlier point for reuse in the process. Compacting of the material remaining after the removal of water provides a material safe for use as desired.

be fed into a compatible sewage system.

A second or dry embodiment follows the same general steps without the addition of water or other liquids and providing for compacting prior to sterilizing in an irradiator which is compatible with the strips produced by the compaction. In this embodiment the removal of liquids would be unnecessary except those removed during compaction or unless a drier final material were desired for some specific utilization. An alternate step in either embodiment would include ozonizing prior to sterilizing.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of this invention will be apparent from a study of the written description and the drawings, in which:

FIG. I is a flow diagram of one embodiment of the present invention; and

FIG. 2 is a flow diagram of a second embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, a flow diagram shows an input 10 for input of refuse being delivered to a disposal site. Typically refuse trucks will deliver refuse which will be loaded into a hopper 'or other feed device for feeding the refuse to a hammer mill grinder ll. Refuse is mostly dry bulky material and can be fed by a belt conveyor to the top of a large hopper from where it can be gravity fed into the hammer mill II from above or a screw conveyor can feed it from other locations. Hammer mill I1 is used to pulverize the refuse including paper, glass, metal cans, and the like, substantially reduce the volume of the waste materials. The pulverized refuse is fed to a separator 12 for separating metal, rocks, and heavier items from the bulk of the refuse such as the pulp materials and the garbage. This may-be done by the addition of water and then regulating the velocity of the flow so that the heavier items will settle while the lighter materials with a lesser density will continue with the flow of the liquid. Other means may also be used such as magnetic removal of ferric-type metals. The input 13 is for the input of water while output 14 indicates the removal of the denser materials. These materials are removed because they may be reusable when separated and because their presence might damage pumps and the irradiator. At any rate a slurry is fed from the separator having the water and lighter solids therein. This slurry may be more thoroughly mixed and more finely ground in the grinder mixer 15 to form a much more uniform slurry for the irradiator 16. lrradiator l6 acts as a sterilizer for the slurry passing through it and may be of that design described in Pat. application Ser. No. 690,475 filed Dec. [4, 1967, for Radiation Treatment Method and Apparatus for Decontamination of Polluted Fluid for which I am one of the inventors or any other of the many available irradiators may be utilized. However, it is advantageous to pass the slurry between parallel plates of gamma radiation which plates can provide a uniform field of radiation therebetween to give a more substantial kill of bacteria, and the like. Ozonation of the refuse may take place in the hammer mill 11 or in the slurry at separator 12 or? both places (or neither) and the input of ozone is illustrated at 19. This step serves two purposes: First to reduce the odor of the refuse at the earliest point and second to provide a more effective kill of microbiological agents when combined with the radiation sterilizer.

The slurry passing from the irradiator 16 may be fed directly into a compatible sewage system for disposal in a combined operation and this is'shown at 17 as a dashed line to indicate that this is an optional means of disposing of the slurry. Otherwise a portion of the liquid must be removed from the slurry and this may be done in several ways but one preferred way is to use a centrifuge 18 which may be a filter drum type centrifuge wherein a drum is perforated and rotated with the solid particles being retained at the inner wall of the drum while the liquid passes through the perforations for removal from the centrifuge. These machines may be continuous in action by providing stationary scrappers to continuously remove the solid material. However, it should be clear that a drum centrifuge could also be used as could other means for removing the liquid. The liquid leaves the centrifuge at 20 and advantageously may be fed back into the separator and reused. The partially dried refuse is finally compacted in a compactor 21 to reduce the volume to the smallest possible size. The compacted material leaving the compactor 21 at output 22 is safe for use as desired and may be used in land fill without fear of pollution of grounds or surface waters but it should be clear that the material is well suited for other uses such as in the production of fertilizer and other soil enrichment uses. Also, the present invention is well suited for separating the pulp materials for reuse should this become sufficiently economical.

it will be clear to those skilled in the art, that a process has been provided for disposing of refuse having a combination of steps including a first grinding in a hammer mill 11, then separating denser materials such as metals at separator 12 while making the refuse into a slurry by adding water, and a second grinding and mixing of the water and ground refuse in grinder 15. Sterilizing of the slurry in irradiator 16 prior to removing water from the slurry in centrifuge 18 and compacting the remaining material for utilization as desired. Water being removed from the slurry may be fedback for reuse in the process. An alternative process would pass the slurry into a compatible community sewage system at 17. Referring now to FIG. 2 a second embodiment has an input which may be the same as input 10 of FIG. 1, as may be the hammer mill 31 be the same as hammer mill 12. The refuse is ground in the hammer mill 31 to make small particles without the large voids such as found in cans, glass bottles, paper cartons, and the like. The pulverized refuse from hammer mill 31 has materials removed as desired in separator 32 which may be a magnetic apparatus for removing ferrous metals, and the like, which will be removed for reuse at 33. The pulverized refuse is next compacted in a compactor 28 which will normally remove some of the moisture that is normally found in the refuse at 29. The compactor 28 will normally be of a type to extrude one or more continuous strips of compacted refuse each strip being sufficiently thin for substantial kill of bacteria, and the like, when passed through irradiator 34. As can be seen the thickness of the extruded strips of compacted refuse will depend upon the design of the irradiator, the strength of its source of radiation, as well as kill desired in sterilizing the refuse. While many irradiator designs are available, it is preferred to use one which passes each strip of material between parallel plates of sources of radiation such as plates of cobalt 60 or cesium 137, or similar radioactive materials. The irradiated and compacted strips will then be packaged or loaded depending upon the utilization of the material but generally the strips will be cut to size in cutter 35 and packaged or loaded at output 36 for shipment to a land fill site or to a factory for commercial utilization without fear of pollution or spreading of disease. As in the first embodiment ozonation could be provided in this embodiment by the addition of ozone from an ozone generator at or following the hammer mill 31.

It should now be clear that an embodiment of the present invention has been provided including grinding refuse in a hammer mill 31, separating materials as desired in separator 32, compacting and dewatering the ground refuse in compactor 28, irradiating the compacted refuse in a radiation sterilizer 34 and cutting and packing or loading the final product in cutter 35.

It should be clear that variations are contemplated for the present process which is adapted, for instance, for adding additional stages of separating the refuse for a fuller use of the materials in the refuse and it is contemplated that large dense objects may be required to be screened prior to the refuse entering the system. Also, other types of radiation sterilizers, such as linear accelerators are contemplated for use in the present invention. However, these are contemplated as being within in the spirit and scope of the present invention.

This invention is not to be construed as limited to the particular forms disclosed herein, since these are to be regarded as illustrative rather than restrictive.

I claim:

1. A refuse disposal method for the safe disposal of garbage, trash, and the like, comprising the steps of:

a. grinding said refuse for breaking said refuse into smaller components;

b. adding liquid to said ground refuse;

c. separating predetermined materials from said ground refuse;

d. mixing said ground refuse having portions removed therefrom with said liquid to form a slurry;

e. irradiating said slurry with gamma radiation;

f. centrifuging said slurry to remove liquid therefrom;

g. feeding back said liquid removed by centrifuging to add to said ground refuse as a portion of the liquid added thereto in step (b); and

h. compacting and packaging said irradiated refuse having liquid removed therefrom, whereby said refuse is reduced to a usable form.

2. The process according to claim 1 in which the steps of separating predetermined materials from said ground refuse includes separating metallic materials from said refuse.

3. The method according to claim 1 but including separating denser materials from said ground refuse.

4. The method according to claim 1 but including cutting and packaging said irradiated refuse.

5. The method according to claim 1 but including the step of ozonizing said refuse prior to irradiating said slurry. 

1. A refuse disposal method for the safe disposal of garbage, trash, and the like, comprising the steps of: a. grinding said refuse for breaking said refuse into smaller components; b. adding liquid to said ground refuse; c. separating predetermined materials from said ground refuse; d. mixing said ground refuse having portions removed therefrom with said liquid to form a slurry; e. irradiating said slurry with gamma radiation; f. centrifuging said slurry to remove liquid therefrom; g. feeding back said liquid removed by centrifuging to add to said ground refuse as a portion of the liquid added thereto in step (b); and h. compacting and packaging said irradiated refuse having liquid removed therefrom, whereby said refuse is reduced to a usable form.
 2. The process according to claim 1 in which the steps of separating predetermined materials from said ground refuse includes separating metallic materials from said refuse.
 3. The method according to claim 1 but including separating denser materials from said ground refuse.
 4. The method according to claim 1 but including cutting and packaging said irradiated refuse.
 5. The method according to claim 1 but including the step of ozonizing said refuse prior to irradiating said slurry. 